package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.config.RedissonConfig;
import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.RedisSystemException;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.time.LocalDateTime;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private IVoucherOrderService voucherOrderService;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private RedissonClient redissonClient;



    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT  = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    private IVoucherOrderService proxy;


    //线程池
    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

//    //线程任务 获取消息队列
//    private class VoucherOrderHandler implements Runnable {
//        String queueName = "stream.orders";
//        @Override
//        public void run() {
//            while (true) {
//                try {
//                    //获取消息队列中的订单信息 take 没有元素的时候会阻塞
//                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
//                            Consumer.from("g1", "c1"),
//                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
//                            StreamOffset.create(queueName, ReadOffset.lastConsumed()));
//                    //判断消息获取是否成功
//                    //没有 再次尝试
//                    if(list == null || list.isEmpty()){
//                        continue;
//                    }
//                    //有 下单
//                    //解析订单
//                    MapRecord<String, Object, Object> record = list.get(0);
//                    //键值对
//                    Map<Object, Object> values = record.getValue();
//
//                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(),true);
//
//                    //下单
//                    handleVoucherOrder(voucherOrder);
//
//                    //ACK确认
//                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
//                } catch (Exception e) {
//                    log.info("处理时异常",e);
//                    handlePendingList();
//                }
//            }
//
//        }
//
//        private void handlePendingList() {
//            while (true) {
//                try {
//                    //获取pending list的订单信息 take 没有元素的时候会阻塞
//                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
//                            Consumer.from("g1", "c1"),
//                            StreamReadOptions.empty().count(1),
//                            StreamOffset.create(queueName, ReadOffset.from("0")));
//                    //说明pending list没有消息 结束循环
//                    if(list == null || list.isEmpty()){
//                        break;
//                    }
//                    //有 下单
//                    //解析订单
//                    MapRecord<String, Object, Object> record = list.get(0);
//                    //键值对
//                    Map<Object, Object> values = record.getValue();
//
//                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(),true);
//
//                    //下单
//                    handleVoucherOrder(voucherOrder);
//
//                    //ACK确认
//                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
//                } catch (Exception e) {
//                    log.info("处理pending list时异常",e);
//                    try {
//                        Thread.sleep(20);
//                    } catch (InterruptedException ex) {
//                        throw new RuntimeException(ex);
//                    }
//                }
//            }
//
//        }
//    }



    //初始化后就执行
    @PostConstruct
    private void init() {
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }

    //阻塞队列
    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);

    //线程任务
    private class VoucherOrderHandler implements Runnable {
        @Override
        public void run() {
            while (true) {
                //获取队列中的订单信息 take 没有元素的时候会阻塞
                try {
                    VoucherOrder voucherOrder = orderTasks.take();
                    //创建订单
                    handleVoucherOrder(voucherOrder);
                } catch (Exception e) {
                    log.info("处理时异常",e);
                }
            }

        }
    }

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        //获取用户
        Long userId = voucherOrder.getUserId();
        //创建锁对象
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        //获取代理对象 无参数 不等待 直接返回
        boolean isLock = lock.tryLock();
        if (!isLock) {
            //获取锁失败
            log.info("不允许重复下单");
            return;
        }
        try {
             proxy.createVoucherOrder2(voucherOrder);
        } catch (IllegalStateException e) {
            throw new RuntimeException(e);
        } finally {
            lock.unlock();
        }
    }

//    public Result seckillVoucher(Long voucherId) {
//        //获取用户id
//        Long userId = UserHolder.getUser().getId();
//        long orderId = redisIdWorker.nextId("order");
//        //执行lua脚本 脚本 key类型参数 其他类型参数
//        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT, Collections.emptyList(),
//                voucherId.toString(), userId.toString(), String.valueOf(orderId));
//        //判断结果是否是0
//        int r = result.intValue();
//        if(r != 0){
//            //不为0 没有购买资格
//            return Result.fail(r == 1 ? "库存不足" : "一人限购一单");
//        }
//
//        //为0
//        // 将信息保存到阻塞队列
//        //获取代理对象
//        proxy = (IVoucherOrderService) AopContext.currentProxy();
//
//        //返回订单id
//        return Result.ok(orderId);
//
//    }

    public Result seckillVoucher(Long voucherId) {
        //获取用户id
        Long userId = UserHolder.getUser().getId();
        //执行lua脚本 脚本 key类型参数 其他类型参数
        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT, Collections.emptyList(),
                voucherId.toString(), userId.toString());
        //判断结果是否是0
        int r = result.intValue();
        if(r != 0){
            //不为0 没有购买资格
            return Result.fail(r == 1 ? "库存不足" : "一人限购一单");
        }

        //为0
        // 将信息保存到阻塞队列
        //6.创建订单
        VoucherOrder voucherOrder = new VoucherOrder();
        //6.1订单id
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        //6.2用户id
        voucherOrder.setUserId(userId);
        //6.3优惠卷id
        voucherOrder.setVoucherId(voucherId);
        //放入阻塞队列
        orderTasks.add(voucherOrder);
        //获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();

        //返回订单id
        return Result.ok(orderId);

    }

    @Override
    @Transactional
    public void createVoucherOrder2(VoucherOrder voucherOrder) {
        //一人一单
        Long userId = voucherOrder.getUserId();

        //查询订单
        int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();

        if (count > 0) {
            //用户已经买过
            log.info("用户已经购买过");
            return ;
        }

        //5.扣减库存
        boolean status = seckillVoucherService.update()
                .setSql("stock = stock - 1") // set stock = stock - 1
                .eq("voucher_id", voucherOrder.getVoucherId()) // where id = ? and stack > 0
                .gt("stock", 0)
                .update();
        if (!status) {
            log.info("库存不足");
            return ;
        }

        voucherOrderService.save(voucherOrder);

    }

//    public Result seckillVoucher(Long voucherId) {
//
//        //1.查询优惠卷
//        SeckillVoucher seckillVoucher = seckillVoucherService.getById(voucherId);
//
//        //2.判断是否开始
//        if (seckillVoucher.getBeginTime().isAfter(LocalDateTime.now())) {
//            return Result.fail("秒杀尚未开始！");
//        }
//
//        //3.判断是否结束
//        if (seckillVoucher.getEndTime().isBefore(LocalDateTime.now())) {
//            return Result.fail("秒杀已经结束！");
//        }
//
//        //4，是否充足
//        if (seckillVoucher.getStock() < 1) {
//            return Result.fail("秒杀卷数量不足！");
//        }
//
//        Long userId = UserHolder.getUser().getId();
//        //intern()去常量池寻找 事务提交完再释放锁
////        synchronized (userId.toString().intern()) {
//        //创建锁对象
////        SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
//        RLock lock = redissonClient.getLock("lock:order:" + userId);
//        //获取代理对象 无参数 不等待 直接返回
//        boolean isLock = lock.tryLock();
//        if (!isLock) {
//            //获取锁失败
//            return Result.fail("不允许重复下单！");
//        }
//
//        try {
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        } catch (IllegalStateException e) {
//            throw new RuntimeException(e);
//        } finally {
//            lock.unlock();
//        }
////        }
//    }

    @Transactional
    public Result createVoucherOrder(Long voucherId) {
        //一人一单
        Long userId = UserHolder.getUser().getId();


        //查询订单
        int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();

        if (count > 0) {
            //用户已经买过
            return Result.fail("用户已经购买过!");
        }


        //5.扣减库存
        boolean status = seckillVoucherService.update()
                .setSql("stock = stock - 1") // set stock = stock - 1
                .eq("voucher_id", voucherId) // where id = ? and stack > 0
                .gt("stock", 0)
                .update();
        if (!status) {
            return Result.fail("秒杀卷数量不足！");
        }


        //6.创建订单
        VoucherOrder voucherOrder = new VoucherOrder();

        //6.1订单id
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        //6.2用户id

        voucherOrder.setUserId(userId);

        //6.3优惠卷id
        voucherOrder.setVoucherId(voucherId);
        voucherOrderService.save(voucherOrder);

        //7.返回订单id
        return Result.ok(orderId);
    }
}
